Oil leakage preventive device for transfer feeder

ABSTRACT

There is disclosed a hydraulic leakage proof apparatus for a transfer feeder in which a cam box (7a) containing a cam (8a) and a lever (9) that is oscillated by the cam is placed on or above a press machine (1). The cam box (7a) is formed through its bottom with an elongate opening (7b) through which the lever (9) may pass by a lower end side thereof. The apparatus includes a lower movable cover (16) operatively coupled to the lever (9) and facing downwards so as to cover the elongate opening (7b) while being displaced as the lever (9) is oscillated. The lower movable cover (16) has a lever through-going opening (16b) formed therein through which the lever (9) may pass. The apparatus further includes a cover member (22) facing downwards so as to cover the lever through-going opening (16b), and a gate plate (14) arranged on the bottom of the cam box (7a) and formed with a rising portion (14a) along an inner peripheral edge of the elongate opening (7b).

This application is a 371 of PCT/JP97/00592, filed Feb. 27, 1997.

TECHNICAL FIELD

The present invention relates to a hydraulic leakage proof apparatus foruse in a transfer feeder, as may be equipped in a transfer press.

BACKGROUND ART

A transfer press typically includes a series of work stations in a pressmachine body which are operable to press form a workpiece sequentially.

Also provided in the press machine body is a transfer feeder that isdesigned to successively carry a workpiece from one of these workstations to another.

Such a transfer feeder includes a pair of transfer bars or lift beamsarranged in parallel and extending in a workpiece transfer direction inwhich a finger means secured to the transfer bars or a cross bar meanssecured to the lift beams via the cross bar carriers serves to hold aworkpiece which is sequentially transferred to these work stations asthe transfer bar or the lift beam pair is driven to move two- orthree-dimensionally.

On the other hand, the transfer feeder referred to above may beimplemented in a form in which an operating mechanism such as for afeed, lift and clamp function can be driven with a power taken from thepress machine proper.

Such mechanisms are typically installed at a site on upstream or at afloor side downstream of the press machine. Where these mechanisms arelocated at the floor or bed side, an inconvenience has hitherto been metthat they may cause a trouble in installing a work carrying in unit forconveying a workpiece into the press machine or installing a workcarrying out unit for conveying a workpiece out of the press machine.

In an attempt to remove such an inconvenience, a modification in thetransfer feeder has been proposed, as disclosed, for example, inJapanese Unexamined Patent Publication Nos. Hei 6-218458 and 6-218459,in which a feed mechanism or a lift mechanism is placed on or above thepress machine.

In a transfer feeder as described in these patent publications, the liftbeams are vertically driven by a lift mechanism with a servo motor as adrive source, a feed mechanism which comprises a feed cam rotatable by apower taken from the press machine and the feed lever adapted to beoscillated by such a feed cam is set up at a site upstream of the pressmachine body and the feed mechanism is operated to drive a cross barcarrier assembly supported on the lift beams in a feed direction.

Also, in a transfer feeder as described in the above identified patentpublications, a feed cam and a feed lever of the feed mechanism areaccommodated in a cam box that is installed at a site upstreams of thepress machine body, and the upper end side of the feed lever issupported by a shaft in the cam box whereas the lower end side of thefeed lever is allowed to project downwards of the cam box, through anelongate opening formed in a lower wall of the cam box and elongated inthe feed direction. And, the lower of the feed lever and the cross barcarrier that is located at an uppermost stream side are coupledtogether.

It should be noted at this point that in such a conventional transferfeeder as just referred to above, a portion of the lubricating system ina press machine is piped locally in such a cam box of the feedmechanism, and various bearing or sliding parts such as a cam shaft andshaft bearing parts, and sliding parts of a cam follower which areattached to a feed cam and a feed lever are thereby lubricated. And, thelubricating oil that flows down from the bearing and sliding parts isallowed to collect in an oil pan mechanism provided on the bottom of thecam box, and thereafter is returned to the lubricating system.

The cam box is commonly formed through its bottom wall with an elongateopening that is required to allow the feed lever to oscillate. Becauseof such a construction, a portion of the oil is allowed to flow downfrom the bearing and sliding parts in the cam box and then to fall on aworkpiece being introduced into the press machine body, tending tohinder an operation required and to contaminate the workpiece, aninconvenience produced.

It is accordingly an object of the present invention to eliminate suchan inconvenience encountered in the prior art and to provide an oil orhydraulic leakage proof apparatus in a transfer feeder, whicheffectively prevent an oil from flowing down through an opening in thebottom wall of a cam box, which in turn prevents any portion of the oilfrom contaminating a workpiece or any part of the press machine and fromhindering an operation thereof.

SUMMARY OF THE INVENTION

In order to achieve the above mentioned object, there is provided inaccordance with the present invention a hydraulic leakage proofapparatus for a transfer feeder in which a cam box containing a cam anda lever adapted to be oscillated by the cam is placed on or above apress machine and is formed through its bottom with an elongate openingthrough which the lever may pass by a lower end side thereof, whichapparatus comprises: a lower movable cover operatively coupled to thesaid lever and facing downwards so as to cover the said elongate openingwhile being displaced as the said lever is oscillated, the said lowermovable cover having a lever through-going opening formed thereinthrough which the said lever may pass; a cover member facing downwardsso as to cover the said lever through-going opening; and a dam memberarranged on the bottom of the said cam box and formed with a risingportion along an inner peripheral edge of the said elongate opening.

According to the construction described above, it can be seen and shouldbe understood that by virtue of the fact that a said lower movable coveris provided facing downwards such as to cover the said elongate openingwhile being displaced along the same as the lever is oscillated, anyportion of the lubricating oil supplied to such bearing parts of thelever and sliding parts of the cam, if allowed to fall down, iseffectively prevented from leaking through the said elongate opening.

Also, since a said cover member, which is associated with a said lever,is arranged facing downwards so as to cover a said lever through-goingopening which is formed in the said lever, any oil leakage whatsoeverfrom the said lever through-going opening can effectively be prevented.

Also, a said dam member being provided having a rising portion servingto prevent a collection of the lubricating oil on the bottom of the cambox from leaking through the elongate opening, any possible hindrance toan operation of the press machine by a portion of the lubricating oilthat may leak and any likewise possible contamination of a workpiece ora work site are effectively prevented.

In the construction noted above, further a guide means may be providedfor guiding the displacement of the said lower movable cover.

According to this construction, it can be seen and should be appreciatedthat because of the ability for the said lower movable cover to movesmoothly as the lever is oscillated, there should be no generation anoise or a vibration during the operation.

Also, a guide member may be mounted on an outer peripheral surface ofthe said lever so as to be sloped; and an upper movable cover may bemounted at a lower end side of said guide member and having one end sidepivotally coupled to said lever and the other end side adapted to bemoved over said lower movable cover.

According to the construction just mentioned, it can be seen and shouldbe understood that with a portion of the lubricating oil that falls overthe outer peripheral surface being first guided to the side of a saidupper movable cover via the guide member and thereafter allowed to flowndown on the bottom side of the cam box, the amount of oil that may falldirectly onto the lower movable cover can be diminished, thereby keepingthe lubricating oil from falling in an appreciable amount on the lowermovable cover and thus rendering the system substantially completelyhydraulic leakage free.

Further, in the apparatus noted the said lower movable cover may be of acollapsible structure deformable in a longitudinal direction of the saidelongate opening.

In the construction just mentioned, the lower movable cover can bereduced in size with its length substantially equal to that of theelongate opening, thereby permitting the space of installation thereforto be minimized.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will better be understood from the followingdetailed description and the drawings attached hereto showing certainillustrative embodiments of the present invention. In this connection,it should be noted that such embodiments as illustrated in theaccompanying drawings are intended in no way to limit the presentinvention but to facilitate an explanation and understanding thereof.

In the accompanying drawings:

FIG. 1 is a front view illustrating a transfer press that is equippedwith a certain embodiment of the hydraulic leakage proof apparatusconstructed in accordance with the present invention;

FIG. 2 is a cross sectional view of a feeder means that is provided inthe hydraulic leakage proof apparatus in the illustrated embodiment ofthe present invention;

FIG. 3 is a plan view as seen according to the arrow III in FIG. 2;

FIG. 4 is an enlarged cross sectional view taken along the line IV--IVin FIG. 2; and

FIG. 5 is an enlarged cross sectional view taken along the line V--V inFIG. 2.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, suitable embodiments of the present invention with respectto a hydraulic leakage proof apparatus for use in a transfer feeder areset forth with reference to the accompanying drawings hereof.

A transfer feeder as shown in FIG. 1 is designed for use in a transferpress and for equipment in a press machine body 1 thereof. The feederincludes a pair of lift beams 2 which extend in a feed direction X thatare adapted to be vertically displaced in a lift direction Y by aplurality of lift means 3 which are equally spaced apart from oneanother in the feed direction X.

Each of the lift means 3 includes a lift motor 3a that is constituted bya servo motor, where the lift motors 3a act to simultaneously displace aplurality of lifting rods 3b vertically in the lift direction Y. And,the lower end of each of the lifting rods 3b is coupled to the lift beam2 so that the two parallel lift beams 2 may be displaced simultaneouslyas the lifting rods 3b are vertically displaced.

Each of the lift beams 2 has a plurality of cross bar carriers 4supported thereof which are spaced apart from one another in the feeddirection X.

Each of the cross bar carriers 4 comprises a principal carrier 4₁ and asubsidiary carrier 4₂ each of which has at its both ends a pair of upperand lower rollers 5 rotatably supported. A guide rail (not shown) isprovided beneath each of the lift beams 2 extending over its length.With two such guide rails being arranged between the upper and lowerrollers 5, the principal and subsidiary carriers 4₁ and 4₂ in each pairare suspended down the lift bars 2 so as to be displaceable in the feeddirections X along the guide rails.

Two successive principal carriers 4₁ are coupled together by aconnecting rod 6 which is provided beneath the lift beams 2 so that theymay be reciprocated in the feed direction X by a feed means 7simultaneously. Also, the principal and subsidiary carriers 4₁ and 4₂ ineach pair are coupled together by a shift means 10.

As shown in FIG. 1, the feed means 7 includes in an upstream site of thepress machine body 1 a cam box 7a in which a cam shaft 8 is providedthat is rotatable by a power taken from the press machine body 1 insynchronism with an operation thereof.

The cam shaft 8 is supported horizontally in a direction orthogonal tothe feed direction X. And, the cam shaft 8 has a feed cam 8a coupledthereto which is constituted of a positive motion cam, with which inperipheral contact a cam follower 8b is arranged that is rotatablysupported on a feed lever 9.

The feed lever 9 in its upper end side is supported on the cam box 7a bya supporting shaft 11 so that a rotation of the feed cam 8a may causethe lower end side of the feed lever 9 to oscillate in the feeddirection X about the supporting shaft 11. Further, the lower end of thefeed lever 9 and the principal carrier 4₁ of the cross bar carrier 4that is located at the most upstream side are coupled together by a link12 so that an oscillation of the feed lever 9 may cause all of the crossbar carriers 4 to reciprocate in the feed direction X together incadence.

On the other hand, the cam box 7a is formed in its bottom surface withan elongate opening 7b that extends in the feed direction X, throughwhich the lower end side of the feed lever 9 is arranged to projectdownward

And, above the elongate opening 7b there is provided a hydraulic leakageproof apparatus according to the present invention, which is designed toprevent a lubricating oil that has lubricated various bearing andsliding parts from leaking or running away from the cam box 7a.

The hydraulic leakage proof apparatus, as is shown in FIGS. 2 to 4,includes a dam member 14 that is mounted on an under surface of theperipheral area of the elongate opening 7b which is formed through thebottom of the cam box 7a.

The gate plate 14 as shown in FIG. 3 is here in the form of a two partconstruction divided by a longitudinal center line and as shown in FIG.4 as well is formed with a rising portion 14a which penetrates upwardthrough the elongate opening 7b along the inner peripheral edge of theelongate opening 7b so that any lubricating oil which may collect in thecam box 7a may not leak out of the elongate opening 7b. Also, as shownin FIG. 3, the dam member 14 is formed in its bottom surface with anoutlet opening 14b. Further, the base of the dam member 14 is providedabove it with a guide means 15, here constituted of a pair of guiderails which are located at both sides of the rising portion 14a andextend parallel to the feed direction X. On this guide means 15 isarranged to rest a lower movable cover 16 via rollers 17.

The lower movable cover 16 is constituted of a plate which isapproximately twice longer than the whole length of the elongate opening7b and has both sides bent downwards. The rollers 17 are rotatablysupported at one end side and midway of the bent portions 16a so thatthey may roll over the guide means 15 as the lower movable cover 16 isdisplaced.

Also, a pair of projections 18 are provided midway of the lower movablecover 16 in its longitudinal direction as rising on its both sidesupwards.

Each of the two projections 18 are formed with a vertically elongatedrecess 18a for accepting a movable member 19 adapted to be slidablyinserted therein vertically and thereby fitted therewith.

The movable member 19 has one end side rotatably supported by each ofpins 20 and midway thereof, the pins 20 being secured to both sidesurfaces of the feed lever 9 so that an oscillation of the latter maycause the lower movable cover 16 to reciprocate in the feed direction Xvia the projections 18. Further, the other end side of each of the pins20 is supported by a cover member 22 as will be described later.

The lower movable cover 16 is formed its midway with the above mentionedthrough-going opening 16b passing through the feed lever 9. A dam plate16c is provided so as to surround the lever through-going opening 16b.At both sides of the feed lever 9 there stand a pair of cover members 22as mentioned above having a cross sectional configuration in the form ofa reversed "L" so as to cover upwards of the lever through-going opening16b.

The dam plate 16c is designed to prevent the oil that may fall andcollect on the surface of the lower movable cover 16 from flowing overthe surface into the lever through-going opening 16. Also, the covermember 22 is dimensioned to be a bit longer than the lever through-goingopening 16b and to have a lower edge configured to be a part of an arcwhich center is on the supporting shaft 11 so that covering upwards ofthe lever through-going opening 16b may prevent the lubricating oil thatfalls over the surface of the feed lever 9 from leaking through thelever through-going opening 16b.

Also, further upwards of the cover member 22 there is a guide member 23that projects from each of both sides of the feed lever 9.

These guide members 23 are fastened obliquely to both side surfaces ofthe feed lever 9 to ensure that the oil which may have lubricated theshaft 11 supporting the feed lever 9 may be prevented from fallingdirectly on the cover member 22 or falling on the lower movable cover 16and that the lubricating oil that has flown along the slope of each ofthe guide members 23 may flow on the upper movable cover 25 coupled tothe feed lever 9.

The upper movable cover 25 is located upwards of the lower movable cover16 and is pivotally coupled through a pin 26 at one end side to abracket 9a projecting from the feed lever 9.

Also, the upper movable cover 25 has both sides bent upwards so that thelubricating oil that has fallen from the guide member 23 may not spillover both its sides. And, as shown in FIG. 5, at the other end side ofthe upper movable cover 25 and in its lower part a roller 27 isrotatably supported by a shaft 28 so as capable of rolling over a rail30 formed on the upper surface of the lower movable cover 16.

The hydraulic leakage proof apparatus with the construction so fardescribed operates in a manner as set forth below.

In an operation of the press machine 1, the feed cam 8a is rotated by apower taken from the press machine 1 to cause the lower end of the feedlever 9 to reciprocate in the feed direction X. This causes all thecross bar carriers 4 supported by the lift beam 2 to reciprocate in thefeed direction X and at the same time the lift beams 2 to be verticallydisplaced in the lift direction Y by the lift means 3.

It follows therefore that each pair of cross bar carriers 4 which aretransversely arranged in tandem (not shown) is operable to movetwo-dimensionally both along the feed direction X and along the liftdirection Y so that a workpiece (not shown) held by a suction meanswhich each cross bar carrier pair 4 carries may be transferred from onework station to another in succession so as to be pressed and therebyformed sequentially.

Also, while the press machine is operated, a lubricating systemfurnishes a lubricating oil or hydraulic into various bearing or slidingparts in the cam box 7a, thereby lubricating these parts. The oil andhydraulic that has lubricated the parts such as the bearing or slidingsurfaces of the feed cam 8a and the shaft 11 supporting the feed lever9, while falling over the surface of the feed lever 9, is led by theguide member 23 to the side of the upper movable cover 25, then arrivingon the bottom region of the cam box 7a after passing over the uppermovable cover 25.

The lubricating oil of which a portion is allowed to flow downwards ofthe guide member 23 will effectively be prevented from leaking out ofthe cam box 7a through the elongated opening 7b formed through thebottom of the cam box 7a or the lever through-going opening 16b formedthrough the lower movable cover 16, by virtue of the fact that downwardsof the guide member 23 there are arranged both the lower movable cover16 as covering the elongated opening 7b and the cover member as coveringthe lever through-going opening 16b.

Also, while it is possible that a portion of the lubricating oil mayfall directly on a surface of the lower movable cover 16 which is notcovered by the cover member 22, then the dam plate 16c acts to preventthe oil from flowing over that surface into the lever through-goingopening 16b.

It should further be noted that should the lower end side of feed lever9 be oscillated about the supporting shaft 11 in the feed direction X,then the lower movable cover 16 will be allowed, via the projections 18engaging with the movable elements 19, to reciprocate correspondingly inthe feed direction X, within the positional range indicated by the solidline shifting to the phantom line in FIG. 2.

It can therefore be seen that should the feed lever 9 be oscillated, thelower movable cover 16 will be kept to always cover above the elongatedopening 7b, thereby acting to prevent a portion of the lubricating oilthat may fall there from leaking through the elongated opening 7bwithout fail.

Then, the upper movable cover 25 will simultaneously be reciprocated aswell, in the positional range indicated by the solid line shifting tothe phantom line in FIG. 2, thus permitting a portion of the lubricatingoil that tends to flow down over the guide member 23 sloped to bedirected onto the bottom of the cam box 7a.

The portion of lubricating oil that is caught on the bottom of the cambox 7a can once be returned from the outlet opening 14b formed throughthe bottom of the gate plate 14 to the lubricating system in the pressmachine 1 via a pipe arrangement not shown, and can thereafter befurnished from the lubricating system to the various bearing or slidingparts in the cam box 7a.

It should be noted that while in the embodiment described in theforegoing the lower movable cover 16 is shown as formed of a plate thatis about twice longer than the elongated opening 7b, the same whenformed of a collapsible construction such as in the form of a bellowsmay be sized to be approximately the same in length as the elongatedopening 7b.

It should also be noted that while the present invention has beendescribed in the foregoing in connection with an embodiment thereof thatis carried out in the cam box 7a for the feed means 7 in a transferfeeder, it can be applicable to any other form of the transfer feeder,either two- or three-dimensional, in which for example, a cam mechanismis employed for the lift means or clamp means, where or the cam box isplaced on or above the press machine body 1.

While the present invention has hereinbefore been thereof, it willreadily be appreciated by a person skilled in the art to be obvious thatmany alterations thereof, omissions therefrom and additions thereto canbe made without departing from the essence and the scope of the presentinvention. Accordingly, it should be understood that the presentinvention is not limited to the specific embodiments thereof set outabove, but includes all possible embodiments thereof that can be madewithin the scope with respect to the features specifically set forth inthe appended claims and encompasses all the equivalents thereof.

What is claimed is:
 1. A hydraulic leakage proof apparatus for atransfer feeder in which a cam box containing a cam and a lever adaptedto be oscillated by the cam is placed on or above a press machine and isformed through its bottom with an elongate opening through which thelever may pass by a lower end side thereof, the apparatus comprising:alower movable cover operatively coupled to said lever and facingdownwards so as to cover said elongate opening while being displaced assaid lever is oscillated, said lower movable cover having a leverthrough-going opening formed therein through which said lever may pass;a cover member facing downwards so as to cover said lever through-goingopening; and a dam member arranged on the bottom of said cam box andformed with a rising portion along an inner peripheral edge of saidelongate opening.
 2. A hydraulic leakage proof apparatus as set forth inclaim 1, further comprising a guide means for guiding the displacementof said lower movable cover.
 3. A hydraulic leakage proof apparatus asset forth in claim 1, further comprising:a guide member mounted on anouter peripheral surface of said lever so as to be sloped; and an uppermovable cover mounted at a lower end side of said guide member andhaving one end side pivotally coupled to said lever and the other endside adapted to be moved over said lower movable cover.
 4. A hydraulicleakage proof apparatus as set forth in claim 1, in which said lowermovable cover is of a collapsible structure deformable in a longitudinaldirection of said elongate opening.